Ophthalmic preparations

ABSTRACT

The present invention provides ophthalmic formulations containing cyclosporine, methods for preparing the formulation, and methods for using the formulation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/714,274, filed Mar. 6, 2007, which claims priority from U.S.Provisional Application Nos. 60/779,420, filed Mar. 7, 2006, and60/837,294, filed Aug. 14, 2006. The contents of these applications arehereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The invention is directed to ophthalmic formulations, methods forpreparing the ophthalmic formulation, and methods of using theophthalmic formulation.

BACKGROUND

Most ocular medications may be administered topically to treat surfaceas well as intraocular disorders. This route is often preferred for themanagement of various pathological diseases that affect the anteriorchamber of the eye, for two main reasons: (1) it is more convenientlyadministered and (2) provides a higher ratio of ocular to systemic druglevels. To be administered topically and to achieve the necessarypatient compliance, the medication must present a good local tolerance.

Cyclosporine is a known immunosuppressant, which acts by reducinginflammatory cells such as activated lymphocytes in the conjunctiva(Kunert et al., Arch Opthalmol., 118:1489-96, 2000) or by increasing thenumber of mucin secreting goblet cells (Kunert et al., Arch Opthalmol.,120:330-7, 2002). Over the years, Cyclosporine A (CsA) has beenevaluated for numerous potential applications in opthalmology.

New developments in the topical delivery of CsA can be divided in twogeneral areas of research: new delivery systems, such as solutions,ointments, colloidal carriers and drug impregnated contact lenses, andchemical modifications of drugs or prodrugs.

At the present time, only one ophthalmic formulation of CsA iscommercially available, which is currently marketed as Restasis®. Theextensive literature on the delivery of CsA to the eye (Lallemand etal., European Journal of Pharmaceutics and Biopharmaceutics 56: 307-318,2003; Nussenblatt et al., Am. J. Opthalmol. 112: 138-146, 1991; Masudaet al., Lancet 1: 1093-1096, 1989; Georganas et al., Clin. Rheumatol.15: 189-192, 1996; Prummel et al., N. Engl. J. Med. 321: 1353-1359,1989; Reinhard et al., Opthalmologe 94: 496-500, 1997) reflects thegreat medical interest and the pharmaco-economical aspects of thischallenge. Despite a poor intraocular penetration, topical CsA has beensuccessfully used in a variety of immune-mediated ocular surfacephenomena such as vernal conjunctivitis, dry eye syndrome and theprevention of corneal allograft rejection. For example, Cross et al.reported that topical cyclosporine eye drop therapy not only improvedthe signs and symptoms of dry eye disease, but also resulted in highpatient satisfaction, fewer patients with chronic dry eye visiting theophthalmologist, and less ancillary drug use (Manag. Care Interface2002; 15:44-49).

One obstacle to preparing an ophthalmic CsA formulation is that CsAcannot be prepared in formulations based on the commonly used aqueousophthalmic vehicles because of both its hydrophobicity (log P=3.0) andits extremely low aqueous solubility at 6.6 mg/ml. Therefore, in moststudies, CsA was dissolved and administered in vegetable oils. However,these media are poorly tolerated, resulting in relatively low ocularavailability. Also, formulations prepared in these media have shortshelf lives.

Oil-in-water emulsions are particularly useful in the delivery oflipophilic drugs. In vivo data from early studies confirmed thatemulsions could be effective topical ophthalmic drug delivery systems,with a potential for sustained drug release.

The product currently on the market, Restasis®, is packaged in singleunit doses to avoid microbial contamination because it does not containany preservatives. It would be highly desired to have a preparation tobe dispensed in a multi-dose container.

Therefore, there is a need for an ideal topical ocular formulation ofCsA, which fulfills several requirements: (1) the formulation must bewell tolerated, or non-irritating to the eye, (2) the formulation mustbe easy to administer, (3) the formulation ideally has an increased CsAresidence time in the eye, (4) systemic absorption of the formulationshould be avoided because the toxic CsA concentration in blood is above300 ng/ml, (5) the formulation should have a long shelf life, and (6)the formulation should be easily manufactured.

The present invention satisfies the needs in the field by providingstable, non-irritating emulsion formulations of CsA suitable forophthalmic application, and methods for preparing and using theformulations.

SUMMARY

One aspect of the invention relates to an ophthalmic formulationcomprising: (a) cyclosporine or a derivative thereof, (b) at least onesolvent, (c) at least one oil, (d) at least one surfactant, (e) at leastone preservative, and (f) water or buffer. In one embodiment, thecyclosporine (Cs) or a derivative thereof can be present in (a) a solidnanoparticulate state; (b) a solid microparticulate state; (c)solubilized; or (d) any combination thereof. An exemplary cyclosporineuseful in the invention is cyclosporine A (CsA).

In one embodiment of the invention, the ophthalmic formulation furthercomprises a viscosity modifier, such as a cellulose derivative, apolysaccharide or a synthetic polymer.

In another embodiment of the invention, the formulation is a mixture ofparticles of cyclosporine or a derivative thereof suspended in emulsiondroplets and sterically stabilized particulate cyclosporine or aderivative thereof in water or buffer.

Another aspect of the invention is directed to an opthalmic cyclosporinecomposition which is cationic. The cationic nature of the formulationresults in an increased residency in the eye, producing a more effectivedosage form. The cationic nature of the dosage form can result, forexample, from the inclusion of a cationic preservative.

In yet another embodiment, the formulation comprises globules of oilcomprising dissolved cyclosporine or a derivative thereof. The globulescan have a diameter, for example, of less than about 10 microns, lessthan about 9 micros, less than about 8 microns, less than about 7microns, less than about 6 microns, less than about 5 microns, less thanabout 4 microns, less than about 3 microns, less than about 2 microns,less than about 1000 nm, less than about 900 nm, less than about 800 nm,less than about 700 nm, less than about 600 nm, less than about 500 nm,less than about 400 nm, less than about 300 nm, less than about 290 nm,less than about 280 nm, less than about 270 nm, less than about 260 nm,less than about 250 nm, less than about 240 nm, less than about 230 nm,less than about 220 nm, less than about 210 nm, less than about 200 nm,less than about 190 nm, less than about 180 nm, less than about 170 nm,less than about 160 nm, less than about 150 nm, less than about 140 nm,less than about 130 nm, less than about 120 nm, less than about 110 nm,less than about 100 nm, less than about 90 nm, less than about 80 nm,less than about 70 nm, less than about 60 nm, less than about 50 nm,less than about 40 nm, less than about 30 nm, less than about 20 nm, orless than about 10 nm.

In some embodiments, the oil is selected from the group consisting of,but not limited to, sweet almond oil, apricot seed oil, borage oil,canola oil, coconut oil, corn oil, cotton seed oil, fish oil, jojobabean oil, lard oil, boiled linseed oil, Macadamia nut oil, medium chaintriglycerides (Crodamol GTCC), mineral oil, olive oil, peanut oil,safflower oil, sesame oil, soybean oil, squalene, sunflower seed oil,tricaprylin (1,2,3-trioctanoyl glycerol), and wheat germ oil.

In other embodiments, the solvent is selected from the group consistingof, but not limited to, isopropyl myristate, triacetin,N-methylpyrrolidinone, aliphatic and aromatic alcohols, ethanol,dimethyl sulfoxide, dimethyl acetamide, ethoxydiglycol, polyethyleneglycols, and propylene glycol. Other examples of useful solvents arelong-chain alcohols. Ethanol is an example of a preferred alcohol thatmay be used in the present invention.

In further embodiments, the surfactant is selected from the groupconsisting of, but not limited to, sorbitan esters (such as Span orArlacel), glycerol esters (such as glycerin monostearate), polyethyleneglycol esters (such as polyethylene glycol stearate), block polymers(such as Pluronics®), acrylic polymers (such as Pemulen®), ethoxylatedfatty esters (such as Cremophor® RH-40), ethoxylated alcohols (such asBrij®), ethoxylated fatty acids (such as Tween or Tween 20),monoglycerides, silicon based surfactants and polysorbates. In apreferred embodiment, the surfactant is Polysorbate 80.

In one embodiment of the invention, the ophthalmic formulations of theinvention have anti-microbial properties. In some embodiments, theformulation comprises a preservative suitable for opthalmicadministration. Examples of such a preservative include, but are notlimited to, quaternary ammonium compounds, such ascetyltrimethylammonium bromide, cetylpyridinium chloride, benzethoniumchloride, and benzalkonium chloride. Preferably, the preservative isbenzalkonium chloride.

In a preferred embodiment, the ophthalmic formulation comprises: (a)cyclosporine A, (b) ethanol, (c) medium chain triglycerides, (d)Polysorbate 80, (e) benzalkonium chloride, and (f) phosphate buffer.

Another aspect of the invention is directed to a method for preparingparticles of Cs or a derivative thereof. The method comprises: (a)forming an emulsion base by suspending cyclosporine or a derivativethereof in a mixture of oil, solvent, surfactant, preservative, andwater or buffer, and (b) homogenizing or vigorously stirring theemulsion base, wherein the resultant composition is a mixture ofparticles of cyclosporine or a derivative thereof suspended in emulsiondroplets and sterically stabilized microcrystalline or nanoparticulatecyclosporine or a derivative thereof in the media. Optionally, theemulsion base of step (a) further comprises a viscosity modifier, suchas a cellulose derivative, a polysaccharide or a synthetic polymer. Inone embodiment, the particles of cyclosporine or a derivative thereofhave a diameter of less than about 10 microns, less than about 9microns, less than about 8 microns, less than about 7 microns, less thanabout 6 microns, less than about 5 microns, less than about 4 microns,less than about 3 microns, less than about 2 microns, less than about 1micron, or even smaller in size. In another embodiment, the homogenizingstep is performed via a high-pressure system at 1,000 to 40,000 psi.

Another aspect of the invention is directed to a method for preparingparticles of Cs or a derivative thereof, comprising: (a) dissolvingcyclosporine or a derivative thereof in a mixture of oil, solvent, andsurfactant to form an emulsion pre-mix, (b) adding preservative, andwater or buffer to the emulsion pre-mix, and (c) homogenizing orvigorously stirring the mixture, whereby cyclosporine or a derivativethereof is precipitated into particles. Optionally, the mixture of step(a) or that of step (b) further comprises a viscosity modifier, such asa cellulose derivative, a polysaccharide or a synthetic polymer. In oneembodiment, the diameter of the particles of cyclosporine or aderivative thereof is less than about 10 microns, less than about 9microns, less than about 8 microns, less than about 7 microns, less thanabout 6 microns, less than about 5 microns, less than about 4 microns,less than about 3 microns, less than about 2 microns, or less than about1 micron. In another embodiment, the homogenizing step is performed viaa high-pressure system at 1,000 to 40,000 psi.

In one embodiment, the particles of cyclosporine or a derivativethereof, droplets comprising cyclosporine or a derivative thereof, or acombination thereof, have a mean particle size of less than about 10microns, less than about 9 microns, less than about 8 microns, less thanabout 7 microns, less than about 6 microns, less than about 5 microns,less than about 4 microns, less than about 3 microns, less than about2900 nm, less than about 2800 nm, less than about 2700 nm, less thanabout 2600 nm, less than about 2500 nm, less than about 2400 nm, lessthan about 2300 nm, less than about 2200 nm, less than about 2100 nm,less than about 2000 nm, less than about 1900 nm, less than about 1800nm, less than about 1700 nm, less than about 1600 nm, less than about1500 nm, less than about 1400 nm, less than about 1300 nm, less thanabout 1200 nm, less than about 1100 nm, less than about 1000 nm, lessthan about 900 nm, less than about 800 nm, less than about 700 nm, lessthan about 600 nm, less than about 500 mm, less than about 400 nm, lessthan about 300 nm, less than about 200 nm, or less than about 100 nm,less than about 90 nm, less than about 80 nm, less than about 70 nm,less than about 60 nm, less than about 50 nm, less than about 40 nm,less than about 30 nm, less than about 20 nm, or less than about 10 nm.Preferably, the particles of cyclosporine or a derivative thereof,droplets comprising cyclosporine or a derivative thereof, or acombination thereof have a mean particle size of less than about 3microns in diameter.

In a related aspect, the invention provides a method of treating asubject suffers from a condition, such as an aqueous deficient dry-eyestate, phacoanaphylaxis endophthalmitis, uveitis, keratoconjunctivitis,allergic eye disorders, or immune-modulated eye diseases. The methodcomprises administering a therapeutically effective amount of the CsAformulations of the invention to the eye of a subject in need.

Both the foregoing general description and the following detaileddescription are exemplary and explanatory and are intended to providefurther explanation of the invention as claimed. Other objects,advantages, and novel features will be readily apparent to those skilledin the art from the following detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, and 1C show mean particle size and mean zeta potential forRestasis®, for the cationic micellar nanoparticle (cMNP) formulation ofcyclosporine A prepared according to Example 1, and for the neutralmicellar nanoparticle (nMNP) formulation prepared according to Example2, respectively.

FIG. 2 shows the mean corneal concentration of cyclosporine in a Franzcell-human cornea model. High level of cyclosporine was detected in thecornea for the cMNP formulation, but not for the nMNP formulation orRestasis®.

FIG. 3 depicts the stability data for the cMNP formulation stored at 25°C., 40° C. and 60° C., respectively, in terms of cyclosporine potencyand mean particle size.

FIG. 4 depicts the stability data for the nMNP formulation stored at 25°C., 40° C. and 60° C., respectively, in terms of cyclosporine potencyand mean particle size.

DETAILED DESCRIPTION A. Overview of the Invention

The invention relates to ophthalmic formulations comprising cyclosporineor a derivative thereof and methods of making and using the same. Oneaspect of the present invention is directed to an ophthalmic formulationcomprising: (a) cyclosporine or a derivative thereof, (b) at least onesolvent, (c) at least one oil, (d) at least one surfactant, (e) at leastone preservative, and (f) water or buffer. In one embodiment, thecyclosporine (Cs) or a derivative thereof can be present in (a) a solidnanoparticulate state; (b) a solid microparticulate state; (c)solubilized; or (d) any combination thereof. In another embodiment, theophthalmic formulation further comprises a viscosity modifier, such as acellulose derivative, a polysaccharide or a synthetic polymer.

The cyclosporine can be, for example, cyclosporine A, and thecyclosporine or a derivative thereof can be in an amorphous form,semi-amorphous form, crystalline form, semi-crystalline form, or anycombination thereof.

In one embodiment of the invention, the opthalmic cyclosporinecomposition is cationic. The cationic nature of the formulation canresult in an increased residency in the eye, producing a more effectivedosage form. Moreover, the increased residency in the eye can result ina need for fewer applications, a decreased drug dosage foreffectiveness, and increased patient compliance (as fewer applicationsare desirable to patients). The cationic nature of the dosage form canresult, for example, from the inclusion of a cationic preservative. Anexemplary cationic preservative is benzalkonium chloride.

In another embodiment of the invention, the formulation is a mixture ofparticles of cyclosporine or a derivative thereof suspended in emulsiondroplets and sterically stabilized particulate cyclosporine or aderivative thereof in water or buffer.

Another aspect of the invention encompasses a method of making atri-phasic composition comprising a lipophilic phase, water or a buffer,and particulate cyclosporine or a derivative thereof. The invention alsoencompasses compositions comprising an oil phase that has at least oneoil, at least one solvent, and a surfactant for cyclosporine or aderivative thereof. Two specific methods of making the composition ofthe invention are described. In the first method (“Route I”),cyclosporine or a derivative thereof is milled in an emulsion base. Thismethod requires that cyclosporine or a derivative thereof is poorlysoluble or insoluble in all phases of the oil phase/lipophilic phase andthe water or buffer. In the second method (“Route II”), simultaneousmilling and precipitation of cyclosporine or a derivative thereof in anemulsion base is observed. The second method requires that cyclosporineor a derivative thereof is soluble or partially soluble in one or morephases of the emulsion base.

One benefit of the invention is to provide a method applicable tocyclosporine or a derivative thereof, which is poorly water-soluble,since the conventional method, such as wet milling, is not effective.Another benefit of the invention is that it does not require grindingmedia or specialized grinding process or equipment. The use of suchgrinding media can add cost and complexity to a particle size reductionprocess for cyclosporine.

For Route I, cyclosporine or a derivative thereof is first suspended ina mixture of a non-miscible liquid, such as an oil, solvent,preservative and water or buffer, to form an emulsion base, followed byhomogenization or vigorous stirring of the emulsion base. Optionally,the emulsion base further comprises a viscosity modifier, such as acellulose derivative, a polysaccharide or a synthetic polymer.Nanoparticles can be produced with reciprocating syringeinstrumentation, continuous flow instrumentation, or high speed mixingequipment. High velocity homogenization or vigorous stirring, producingforces of high shear and cavitation, are preferred. High shear processesare preferred as low shear processes can result in larger particle sizesof cyclosporine or a derivative thereof. The resultant composition is acomposite mixture of cyclosporine or a derivative thereof suspended inthe emulsion droplet (nanoemulsion fraction) and sterically stabilizedmicro-/nano-crystalline cyclosporine or a derivative thereof in themedia. This tri-phasic system comprises particulate cyclosporine or aderivative thereof, oil, preservative, and water or buffer. Preferably,the resultant micro/nano-particulate cyclosporine or a derivativethereof has a mean particle size of less than about 3 microns. Smallerparticulate cyclosporine or a derivative thereof can also be obtained,as described below.

Cyclosporine or a derivative thereof can be precipitated out from theoil droplets by adding more of the non-miscible liquid. The precipitatedcyclosporine or a derivative thereof typically has a mean particle sizeof less than about 3 microns. If desired, the particles of cyclosporineor a derivative thereof can be prevented from aggregating or clumpingtogether by incorporating a surfactant or emulsifier, e.g., a “surfacestabilizer.”

Route II is utilized for cyclosporine or a derivative thereof because itis soluble in at least one part of the emulsion base, such as thesolvent, in particular, ethanol. For Route II, cyclosporine or aderivative thereof is dissolved in a mixture of oil, solvent, andsurfactant to form an emulsion pre-mix. Cyclosporine or a derivativethereof remains in soluble form if preservative and water or buffer arenot added to the mixture. Upon the addition of preservative, a viscositymodifier, and water or buffer and the application of shear forces,cyclosporine or a derivative thereof is precipitated intomicro/nano-particles having a mean particle size of less than about 3microns. Nanoparticles can be produced with reciprocating syringeinstrumentation, continuous flow instrumentation, or high speed mixingequipment. High energy input, through high velocity homogenization orvigorous stirring, is a preferred process. The high energy processesreduce the size of the emulsion droplets, thereby exposing a largesurface area to the surrounding aqueous environment. High shearprocesses are preferred, as low shear processes can result in largerparticle sizes. This is followed by precipitation of nanoparticulatecyclosporine or a derivative thereof previously embedded in the emulsionbase. The end product comprises cyclosporine or a derivative thereof insolution and particulate suspension, both distributed between thesolvent, oil, preservative, and water or buffer. Nanoparticulatecyclosporine or a derivative thereof has at least one surface stabilizerassociated with the surface thereof.

If desired, the water miscible oil droplets and nanoparticles ofcyclosporine or a derivative thereof prepared using Route I or Route IImay be filtered through either a 0.2 or 0.45 micron filter. Larger oildroplets and/or particles of cyclosporine or a derivative thereof can becreated by simply increasing the water content, decreasing theoil-stabilizer-solvent content, or reducing the shear in forming the oildroplets.

For the 50× concentrated emulsion base used in Route I or Route II, thecontent of cyclosporine is about 0.1%-10%, the content of solvent isabout 0.1%-20%, the content of oil is about 5%-50%, the content ofsurfactant is about 0.1%-20%, the content of preservative is about0.1%-5%, and the content of the aqueous medium is about 20%-80%, all inw/w percentage. Optionally, the viscosity modifier is present in theemulsion base in the amount of about 0.1% to about 10% (w/w). Thecontent of each ingredient in the final product is the amount abovedivided by 50, with the aqueous medium being the major component, atabout 98% or more.

B. Definitions

The present invention is described herein using several definitions, asset forth below and throughout the application.

As used herein, “about” will be understood by persons of ordinary skillin the art and will vary to some extent depending upon the context inwhich it is used. If there are uses of the term which are not clear topersons of ordinary skill in the art given the context in which it isused, “about” will mean up to plus or minus 10% of the particular term.

The phrase “poorly water-soluble” or “water insoluble” as used hereinrefers to a solubility in water of less than about 30 mg/mL, less thanabout 20 mg/mL, less than about 10 mg/mL, less than about 1 mg/mL, lessthan about 0.1 mg/mL, less than about 0.01 mg/mL or less than about0.001 mg/mL at ambient temperature and pressure and at about pH 7.

The phrase “soluble” as used herein refers to a solubility in water oranother medium selected from the group consisting of greater than about10 mg/mL, greater than about 20 mg/mL, and greater than about 30 mg/mL.

As used herein, the term “subject” is used to mean an animal, preferablya mammal, including a human or non-human. The terms “patient” and“subject” may be used interchangeably.

As used herein, the phrase “therapeutically effective amount” shall meanthat drug dosage that provides the specific pharmacological response forwhich the drug is administered in a significant number of subjects inneed of such treatment. It is emphasized that a therapeuticallyeffective amount of a drug that is administered to a particular subjectin a particular instance will not always be effective in treating theconditions/diseases described herein, even though such dosage is deemedto be a therapeutically effective amount by those of skill in the art.

As used herein, the phrase “cyclosporines and derivatives thereof”include a group of nonpolar cyclic oligopeptides with knownimmunosuppressant activity, as disclosed in U.S. Pat. No. 5,474,979,which is incorporated by reference in its entirety. In addition to themost common form of cyclosporine A, there are several other minormetabolites, cyclosporine B through I, identified. The present inventionintends to include any individual member of the cyclosporine family, aswell as a mixture of two or more members of the family, because thecommercial cyclosporines may contain a mixture of several forms ofcyclosporines, which all share a cyclic peptide structure consisting ofeleven amino acids with a total molecular weight of about 1200. Thecyclosporines and derivatives thereof also include the natural orsynthetic product, as well as any substituents or differentconfigurations of the amino acids, as long as they maintain theimmunosuppressive activity and capability of enhancing or restoring thelacrimal gland tearing. The present invention further encompasses thecyclosporine A derivatives, e.g., methylthio-substituted cyclosporine Aand other alkylthio-substituted cyslosporine A derivatives, as disclosedin U.S. Pat. Nos. 6,254,860 and 6,350,442, each of which is incorporatedby reference in its entirety.

C. Compositions of the Invention

1. Exemplary Compositions

The methods of the invention can produce several different types ofcompositions. A first composition comprises: (1) microparticulate and/ornanoparticulate cyclosporine or a derivative thereof having a meanparticle size of less than about 10 microns and, optionally fornanoparticulate cyclosporine or a derivative thereof, having associatedwith the surface thereof at least one surface stabilizer; (2) at leastone preservative; (3) water or a buffer; and (4) an emulsion pre-mix oroil phase or lipophilic phase comprising at least one oil and optionallyat least one solvent, and/or a viscosity modifier. The composition mayadditionally comprise microcrystalline cyclosporine or a derivativethereof. The particulate cyclosporine or a derivative thereof can bepresent in the water or buffer, oil, solvent, preservative, or acombination thereof. Such a composition is made utilizing Route I.

A second composition comprises: (1) microparticulate and/ornanoparticulate cyclosporine or a derivative thereof having a meanparticle size of less than about 10 microns and, optionally fornanoparticulate cyclosporine or a derivative thereof having associatedwith the surface thereof at least one surface stabilizer; (2) apreservative; (3) water or a buffer; and (4) an emulsion pre-mix or oilphase or lipophilic phase comprising at least one oil, optionally atleast one solvent, solubilized cyclosporine or a derivative thereof,and/or a viscosity modifier. The composition may additionally comprisemicrocrystalline cyclosporine or a derivative thereof. The solubilizedcyclosporine or a derivative thereof may be present in oil, solvent, ora combination thereof. In addition, nanoparticulate cyclosporine or aderivative thereof can be present in the water or buffer, oil, solvent,or a combination thereof. Such a composition is made utilizing Route II.

In a further embodiment of the invention, the solubilized cyclosporineor a derivative thereof can be precipitated out from the emulsiondroplets. The precipitated microparticulate cyclosporine or a derivativethereof has a mean particle size of less than about 10 microns, lessthan about 9 microns, less than about 8 microns, less than about 7microns, less than about 6 microns, less than about 5 microns, less thanabout 4 microns, less than about 3 microns, less than about 2 microns,or about 1 micron or greater. In other embodiments of the invention, atleast about 50%, at least about 60%, at least about 70%, at least about80%, at least about 90%, at least about 95%, or at least about 99% ofthe particles of cyclosporine or a derivative thereof can have adiameter less than the size listed above, e.g., less than about 10microns, less than about 9 microns, etc.

In yet another embodiments of the invention, the nanoparticles ofcyclosporine or a derivative thereof have a diameter of less than about1000 nm, less than about 900 nm, less than about 800 nm, less than about700 nm, less than about 600 nm, less than about 500 nm, less than about400 nm, less than about 300 nm, less than about 290 nm, less than about280 nm, less than about 270 nm, less than about 260 nm, less than about250 nm, less than about 240 nm, less than about 230 nm, less than about220 nm, less than about 210 nm, less than about 200 nm, less than about190 nm, less than about 180 nm, less than about 170 nm, less than about160 nm, less than about 150 nm, less than about 140 nm, less than about130 nm, less than about 120 nm, less than about 110 nm, less than about100 nm, less than about 90 nm, less than about 80 nm, less than about 70nm, less than about 60 nm, less than about 50 nm, less than about 40 nm,less than about 30 nm, less than about 20 nm, or less than about 10 nm.In other embodiments of the invention, at least about 50%, at leastabout 60%, at least about 70%, at least about 80%, at least about 90%,at least about 95%, or at least about 99% of the particles ofcyclosporine or a derivative thereof can have a diameter less than thesize listed above, e.g., less than about 1000 nm, less than about 900nm, etc.

The tri-phasic compositions of the invention are beneficial for severalreasons. First, formulations resulting from the Route II method compriseboth solid and solubilized forms of cyclosporine or a derivativethereof. This enables a resultant pharmaceutical formulation to provideboth immediate release and controlled release of the componentcyclosporine or a derivative thereof, providing for fast onset ofactivity combined with prolonged activity of cyclosporine or aderivative thereof.

The different components of the two types of compositions describedabove can be separated and used independently.

2. Emulsion Globules Comprising Cyclosporine Nanoparticles and/orSolubilized Cyclosporine

The emulsion globules comprising solubilized cyclosporine or aderivative thereof, nanoparticles of cyclosporine or a derivativethereof, or a combination thereof can also be isolated from thesurrounding aqueous or buffer phase and used in therapeutic dosageforms. The emulsion globules can be made using food grade, USP or NFgrade materials suitable for human use applications. Nanoparticulate oilglobules comprising solubilized active pharmaceutical ingredient (API)and methods of making the same are described in U.S. Pat. No. 5,629,021(“the '021 patent”), which is incorporated herein by reference. Theemulsion globules of the invention typically comprise (1) solubilizedcyclosporine or a derivative thereof, particulate cyclosporine or aderivative thereof, or a combination thereof, (2) at least one oil; (3)at least one solvent; (4) at least one preservative; and (5) at leastone surface stabilizer or surfactant. Optionally, the emulsion globulesfurther comprises a viscosity modifier, such as a cellulose derivative,a polysaccharide or a synthetic polymer. Emulsion globules comprisingsolubilized cyclosporine or a derivative thereof, particulatecyclosporine or a derivative thereof, or a combination thereof can beisolated by, for example, filtration.

In general, the emulsion globules comprising solubilized cyclosporine ora derivative thereof, nanoparticles of cyclosporine or a derivativethereof, or a combination thereof comprise a significant quantity ofcyclosporine or a derivative thereof and have diameters of about 10 toabout 1000 nm, with a mean a diameter of less than about 1 micronpreferred, and with the smallest globules filterable through a 0.2micron filter, such as is typically used for microbiologicalpurification. The range of concentration of cyclosporine or a derivativethereof in the globules in the diluted final product can be from about0.01% to about 5%. The emulsion globules can be stored at between about−20° C. and about 40° C. In one embodiment of the invention, at leastabout 50%, at least about 60%, at least about 70%, at least about 80%,or at least about 90% of the globules in the preparation have diametersof less than about 1 micron, less than about 900 nm, less than about 800nm, less than about 700 nm, less than about 600 nm, less than about 500nm, less than about 400 nm, less than about 300 nm, less than about 200nm, or less than about 100 nm.

By varying different parameters of Route I and Route II, the size andintegrity of such globules can be modified. Hence, the stability ofglobules comprising dissolved cyclosporine or a derivative thereof canbe altered to enable the release of cyclosporine or a derivativethereof, either as a solution or precipitate. This is amicroreservoir-dissolution-controlled system, where the drug solids actas depot and, as the solubilized fraction is depleted, more drug isdrawn into solution form the particulate depot. Thus, the emulsionglobules comprising solubilized cyclosporine or a derivative thereofenable controlled cyclosporine or a derivative thereof release overtime.

In addition, the emulsion globules comprising solubilized cyclosporineor a derivative thereof, nanoparticles of cyclosporine or a derivativethereof, or a combination thereof can be diluted with aqueous solutionswithout stability loss. This enables the use of high concentration ofcyclosporine or a derivative thereof, e.g., up to about 10%, in productswhich can be diluted to obtain the final product.

In a preferred embodiment, 50× concentrated cyclosporine formulationcontaining 2.5% w/w cyclosporine is manufactured aseptically. Theparticles of cyclosporine in the concentrated product have a meanparticle size of less than 200 nm. Subsequently, the concentratedproduct is diluted with sterile PBS/saline to achieve 0.05% w/wcyclosporine in the final product, which has similar appearance toRestasis®. The final product is packaged and sealed in 0.4 ml per dose.

D. Methods of Making the Inventive Compositions

Three methods for making the compositions of the invention are describedherein. One benefit of the invention is to provide methods applicable tocyclosporine or a derivative thereof, which is poorly water-soluble.Another benefit of the methods of the invention is that they do notrequire grinding media or specialized grinding process or equipments.The use of such grinding media can add cost and complexity to a particlesize reduction process for an API. Additionally, the methods of theinvention can accommodate amorphous or semi-amorphous forms ofcyclosporine or a derivative thereof. In summary, the three methods areas follows: Route I: cyclosporine or a derivative thereof is insolubleor slightly soluble in any of the components of the formulation; RouteII: cyclosporine or a derivative thereof is soluble or partially solublein at least one of the components of the formulation; and Route III:cyclosporine or a derivative thereof is completely soluble in all of thecomponents of the formulation.

1. Route I

The method of Route I essentially comprises milling cyclosporine or aderivative thereof in an emulsion base. This method requires thatcyclosporine or a derivative thereof is poorly soluble or insoluble inall phases of the oil phase/lipophilic phase and the water or buffer.Hence, cyclosporine or a derivative thereof is first suspended in amixture of a non-miscible liquid, which can comprise at least one oil,at least one solvent, at least one preservative, at least one viscositymodifier, and at least one buffer or water to form an emulsion base,followed by homogenization or vigorous stirring of the emulsion base.Nanoparticles of cyclosporine or a derivative thereof can be producedwith reciprocating syringe instrumentation, continuous flowinstrumentation, or high speed mixing equipment. High velocityhomogenization or vigorous stirring, producing forces of high shear andcavitation, are preferred. High shear processes are preferred as lowshear processes can result in larger particle sizes.

The resultant composition is a composite mixture of cyclosporine or aderivative thereof suspended in the emulsion droplet (nanoemulsionfraction of cyclosporine or a derivative thereof) and stericallystabilized microcrystalline or microparticulate cyclosporine or aderivative thereof in the media. This tri-phasic system comprisesparticulate cyclosporine, oil, preservative and water or buffer.

In one embodiment of the invention, the resultant microparticulatecyclosporine or a derivative thereof has a diameter of less than about10 microns, less than about 9 microns, less than about 8 microns, lessthan about 7 microns, less than about 6 microns, less than about 5microns, less than about 4 microns, less than about 3 microns, less thanabout 2 microns, or greater than about 1 micron.

In another embodiment of the invention, the nanoparticulate cyclosporineor a derivative thereof can have a diameter of less than about 1000 nm,less than about 900 nm, less than about 800 nm, less than about 700 nm,less than about 600 nm, less than about 500 nm, less than about 400 nm,less than about 300 nm, less than about 290 nm, less than about 280 nm,less than about 270 nm, less than about 260 mm, less than about 250 nm,less than about 240 nm, less than about 230 nm, less than about 220 nm,less than about 210 nm, less than about 200 nm, less than about 190 nm,less than about 180 nm, less than about 170 nm, less than about 160 nm,less than about 150 nm, less than about 140 nm, less than about 130 nm,less than about 120 nm, less than about 110 nm, less than about 100 nm,less than about 90 nm, less than about 80 nm, less than about 70 nm,less than about 60 nm, less than about 50 nm, less than about 40 nm,less than about 30 nm, less than about 20 nm, or less than about 10 nm.

In other embodiments of the invention, at least about 50%, at leastabout 60%, at least about 70%, at least about 80%, at least about 90%,at least about 95%, or at least about 99% of the microcrystalline ormicroparticulate cyclosporine or a derivative thereof in a compositioncan have a diameter of less than about 10 microns, less than about 9microns, less than about 8 microns, less than about 7 microns, less thanabout 6 microns, less than about 5 microns, less than about 4 microns,less than about 3 microns, less than about 2 microns, about 1 micron, orgreater than about 1 micron and less than about 2, about 3, about 4,about 5, about 6, about 7, about 8, about 9, or about 10 microns.

In yet other embodiments of the invention, at least about 50%, at leastabout 60%, at least about 70%, at least about 80%, at least about 90%,at least about 95%, or at least about 99% of the nanoparticulatecyclosporine or a derivative thereof can have a diameter of less thanabout 1000 nm, less than about 900 nm, less than about 800 nm, less thanabout 700 nm, less than about 600 nm, less than about 500 nm, less thanabout 400 nm, less than about 300 nm, less than about 290 nm, less thanabout 280 nm, less than about 270 nm, less than about 260 nm, less thanabout 250 nm, less than about 240 nm, less than about 230 nm, less thanabout 220 nm, less than about 210 nm, less than about 200 nm, less thanabout 190 nm, less than about 180 nm, less than about 170 nm, less thanabout 160 nm, less than about 150 nm, less than about 140 nm, less thanabout 130 nm, less than about 120 nm, less than about 110 mm, less thanabout 100 nm, less than about 90 nm, less than about 80 nm, less thanabout 70 nm, less than about 60 nm, less than about 50 nm, less thanabout 40 nm, less than about 30 nm, less than about 20 nm, or less thanabout 10 nm in size.

Cyclosporine or a derivative thereof can be precipitated out from theoil droplets by adding more of the non-miscible liquid. The precipitatedparticles of cyclosporine or a derivative thereof typically have adiameter of less than about 10 microns, less than about 9 microns, lessthan about 8 microns, less than about 7 microns, less than about 6microns, less than about 5 microns, less than about 4 microns, less thanabout 3 microns, less than about 2 microns, or less than about 1 micron.If desired, the particles cyclosporine or a derivative thereof can beprevented from aggregating or clumping together by incorporating asurfactant or emulsifier, e.g., a “surface stabilizer.”

2. Route II and Route III

Routes II and III require that cyclosporine or a derivative thereof issoluble or partially soluble in at least one (Route II) or all of thephases (Route III) of the emulsion base; e.g., that cyclosporine or aderivative thereof is soluble in at least one oil, at least one solvent,at least one preservative, or water or buffer. In some embodiments,Route II or III can comprise the simultaneous milling and precipitationof cyclosporine or a derivative thereof in an emulsion base.

Route II is utilized when cyclosporine or a derivative thereof issoluble in at least one part of the emulsion base, such as the solvent,and Route III is utilized when cyclosporine or a derivative thereof issoluble in all of the components of the emulsion base, such as oil and asolvent. For Routes II and III, cyclosporine or a derivative thereof isdissolved in a mixture of oil, solvent, preservative, viscosity modifierand stabilizer to form an emulsion pre-mix. Cyclosporine or a derivativethereof remains in soluble form if water or buffer is not added to themixture. Upon the addition of water or buffer and the application ofshear forces, cyclosporine or a derivative thereof is precipitated intomicroparticles having a diameter of less than about 10 microns, andnanoparticles having a diameter of less than about 1 micron (asdescribed above in Route I; the same particle sizes are applicable toRoutes II and III). Nanoparticles can be produced with reciprocatingsyringe instrumentation, continuous flow instrumentation, or high speedmixing equipment. High energy input, through high velocityhomogenization or vigorous stirring, is a preferred process. The highenergy processes reduce the size of the emulsion droplets, therebyexposing a large surface area to the surrounding aqueous environment.High shear processes are preferred, as low shear processes can result inlarger particle sizes.

This can be followed by precipitation of nanoparticulate cyclosporine ora derivative thereof previously embedded in the emulsion base. The endproduct comprises cyclosporine or a derivative thereof in solution andparticulate suspension, both distributed between the solvent, oil, andwater or buffer. In one embodiment, nanoparticulate cyclosporine or aderivative thereof has at least one surface stabilizer associated withthe surface thereof.

If desired, the water miscible oil droplets and nanoparticles ofcyclosporine or a derivative thereof prepared using Route I, Route II,or Route III may be filtered through either a 0.2 or 0.45 micron filter.Larger oil droplets and/or particles of cyclosporine or a derivativethereof can be created by simply increasing the water content,decreasing the oil-stabilizer-solvent content, or reducing the shear informing the oil droplets.

For the 50× concentrated emulsion base used in Route I, Route II, orRoute III, the content of cyclosporine is about 0.1%-10%, the content ofsolvent is about 0.1%-20%, the content of oil is about 5%-50%, thecontent of surfactant is about 0.1%-20%, the content of preservative isabout 0.1%-5%, and the content of the aqueous medium is about 20%-80%,all in w/w percentage. Optionally, the viscosity modifier is present inthe emulsion base in the amount of about 0.1% to about 10% (w/w). Thecontent of each ingredient in the final product is the amount abovedivided by 50, with the aqueous medium being the major component, atabout 98% or more.

E. Components of the Methods and Compositions of the Invention

1. Cyclosporine

a. Suitable Cyclosporine and Derivatives Thereof

The phrase “cyclosporines and derivatives thereof” is defined supra, asdisclosed in U.S. Pat. Nos. 5,474,979, 6,254,860, and 6,350,442. Thecyclosporines useful in the present invention include naturallyoccurring cyclosporines, preferably cyclosporines A, B, C, D and G, aswell as synthetic and semi-synthetic cyclosporines and cyclosporinederivatives disclosed in U.S. Pat. Nos. 4,108,985, 4,210,581, 4,220,641,4,384,996, 4,764,503, 4,703,033 and U.K. Patent Application No.2,206,119A, which are hereby incorporated by reference in theirentirety. Preferably, the cyclosporine is cyclosporine A.

b. Particle Size of Cyclosporine

As used herein, the particle size is determined on the basis of theweight average particle size as measured by conventional techniques wellknown to those skilled in the art, such as sedimentation field flowfractionation, laser diffraction, photon correlation spectroscopy (alsoknown as dynamic light scattering), electroacoustic spectroscopy, ordisk centrifugation.

As used herein, “nanoparticulate cyclosporine or a derivative thereof”refers to cyclosporine or a derivative thereof having a diameter of lessthan about 1 micron. An exemplary cyclosporine useful in the inventionis cyclosporine A. “Microcrystalline cyclosporine or a derivativethereof” refers to cyclosporine or a derivative thereof having adiameter of greater than about 1 micron. In other embodiments of theinvention, microparticulate cyclosporine or a derivative thereof have adiameter of less than about 10 microns, less than about 9 microns, lessthan about 8 microns, less than about 7 microns, less than about 6microns, less than about 5 microns, less than about 4 microns, less thanabout 3 microns, less than about 2 microns, or about 1 micron orgreater. In other embodiments of the invention, at least about 50%, atleast about 60%, at least about 70%, at least about 80%, at least about90%, at least about 95%, or at least about 99% of the microparticles ofcyclosporine or a derivative thereof can have a diameter less than thesize listed above, e.g., less than about 10 microns, less than about 9microns, etc.

In yet other embodiments of the invention, nanoparticulate cyclosporineor a derivative thereof has a diameter of less than about 900 nm, lessthan about 800 nm, less than about 700 nm, less than about 600 nm, lessthan about 500 nm, less than about 400 nm, less than about 300 nm, lessthan about 290 nm, less than about 280 nm, less than about 270 nm, lessthan about 260 nm, less than about 250 nm, less than about 240 nm, lessthan about 230 nm, less than about 220 nm, less than about 210 nm, lessthan about 200 nm, less than about 190 nm, less than about 180 nm, lessthan about 170 nm, less than about 160 nm, less than about 150 mm, lessthan about 140 nm, less than about 130 nm, less than about 120 nm, lessthan about 110 nm, less than about 100 nm, less than about 90 nm, lessthan about 80 nm, less than about 70 nm, less than about 60 nm, lessthan about 50 nm, less than about 40 nm, less than about 30 nm, lessthan about 20 nm, or less than about 10 nm. In other embodiments of theinvention, at least about 50%, at least about 60%, at least about 70%,at least about 80%, at least about 90%, at least about 95%, or at leastabout 99% of the nanoparticles of cyclosporine or a derivative thereofcan have a diameter less than the size listed above, e.g., less thanabout 900 nm, less than about 800 nm, etc.

In other embodiments of the invention, at least about 60%, at leastabout 70%, at least about 80%, at least about 90%, at least about 95%,or at least about 99% of the particles of cyclosporine or a derivativethereof, or droplets comprising solubilized cyclosporine or a derivativethereof, have a size less than the mean particle size, less than about 3microns, less than about 2900 nm, less than about 2800 nm, etc.

2. Oils

For both the methods of Route I and Route II and the compositions of theinvention, any suitable oil can be used. Exemplary oils that can be usedinclude, for example, vegetable oils, nut oils, fish oils, lard oil,mineral oils, squalane, tricaprylin, and mixtures thereof. Specificexamples of oils that may be used include, but are not limited to,almond oil (sweet), apricot seed oil, borage oil, canola oil, coconutoil, corn oil, cotton seed oil, fish oil, jojoba bean oil, lard oil,linseed oil (boiled), Macadamia nut oil, medium chain triglycerides,mineral oil, olive oil, peanut oil, safflower oil, sesame oil, soybeanoil, squalene, sunflower seed oil, tricaprylin (1,2,3-trioctanoylglycerol), wheat germ oil, and mixtures thereof.

3. Stabilizers or Surfactants

The stabilizer used in the methods and compositions of the inventionassociates with, or adsorbs, to the surface of the nanoparticulatecyclosporine or a derivative thereof, but does not covalently bind tocyclosporine or a derivative thereof. In addition, the individualstabilizer molecules are preferably free of cross-linkages. Thestabilizer is preferably soluble in water. One or more stabilizers maybe used in the compositions and methods of the invention. As usedherein, the terms “stabilizer”, “surface stabilizer”, and “surfactant”are used interchangeably.

Any suitable nonionic or ionic surfactant may be utilized in thecompositions of the invention, including anionic, cationic, andzwitterionic surfactants. Exemplary stabilizers or surfactants that maybe used in both Routes I and II include, but are not limited to,non-phospholipid surfactants, such as the Tween (polyoxyethylenederivatives of sorbitan fatty acid esters) family of surfactants (e.g.,Tween 20, Tween 60, and Tween 80), nonphenol polyethylene glycol ethers,sorbitan esters (such as Span and Arlacel), glycerol esters (such asglycerin monostearate), polyethylene glycol esters (such as polyethyleneglycol stearate), block polymers (such as Pluronics®), acrylic polymers(such as Pemulen®), ethoxylated fatty esters (such as Cremophor® RH-40),ethoxylated alcohols (such as Brij®), ethoxylated fatty acids,monoglycerides, silicon based surfactants, polysorbates, Tergitol NP-40(Poly(oxy-1,2-ethanediyl), α-(4-nonylphenol)-.omega.-hydroxy, branched[molecular weight average 1980]), and Tergitol NP-70 (a mixedsurfactant—AQ=70%).

4. Solvents

Any suitable solvent can be used in the methods and compositions of theinvention. Exemplary solvents include, but are not limited, to isopropylmyristate, triacetin, N-methyl pyrrolidinone, aliphatic or aromaticalcohols, polyethylene glycols, propylene glycol. An example of analcohol useful in the present invention includes, but is not limited toethanol. Other short chain alcohols and/or amides may be used. Othersolvents include dimethyl sulfoxide, dimethyl acetamide, andethoxydiglycol. Mixtures of solvents can also be used in thecompositions and methods of the invention.

5. Water or Buffer

If the methods and/or compositions of the invention use or comprisewater or a buffer, the aqueous solution is preferably a physiologicallycompatible solution such as water or phosphate buffered saline.

6. Preservatives

The formulations of the invention have anti-microbial properties. Theanti-microbial properties can be associated with the formulation. As anexample, the formulations described herein, in the absence ofcyclosporine, can exhibit antimicrobial activity.

Antimicrobial agents or preservatives are added to nonsterile dosageforms to protect them from microbiological growth or from microorganismsthat are introduced inadvertently during or subsequent to themanufacturing process. In the case of sterile articles used inmulti-dose containers, antimicrobial preservatives are added to inhibitthe growth of microorganisms that may be introduced by repeatedlywithdrawing individual doses.

U.S. Food and Drug Administration guidelines require that antimicrobialeffectiveness, whether inherent in the product (e.g., for an antibioticagent) or whether produced because of the addition of an antimicrobialagent, must be demonstrated for all injections packaged in multiple-dosecontainers or for other products containing antimicrobial preservatives.Antimicrobial effectiveness must be demonstrated for multiple-dosetopical and oral dosage forms, and for other dosage forms such asophthalmic, otic, nasal, irrigation, and dialysis fluids. See USP 25,Section 51, “Antimicrobial Effectiveness Testing.”

The formulations of the invention meet the Antimicrobial EffectivenessTest as described in the United States Pharmacopeia (USP—General Chapter#51). The standard USP testing requires evaluation in fivemicroorganisms: Aspergillus niger (ATCC 16404), Candida albicans (ATCC10231), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027)and Staphylococcus aureus (ATCC 6538).

The formulations of the invention comprise preservatives, e.g., watersoluble quaternary ammonium compounds, such as cetyltrimethylammoniumbromide, cetylpyridinium chloride, benzethonium chloride, andbenzalkonium chloride. Preferably, the preservative is benzalkoniumchloride.

BKC has been used as a preservative in ophthalmic formulations for manyyears. The formulation of the present invention contains BKC at aconcentration that is recognized to be sufficient to qualify the USPPreservative Efficacy testing. There is sufficient literature evidenceavailable to prove preservative efficacy for BKC used in ophthalmicformulations (Handbook of Pharmaceutical Excipients, 3^(rd) edition(2000), edited by Arthur H. Kibbe, published by American PharmaceuticalAssociation and Pharmaceutical Press, pp. 33-35). Hence, the formulationof the invention is suitable for multi-dose packaging.

In the present invention, BKC unexpectedly functions as a cationicagent, which contributes to the prolonged drug residence time. Thisproperty of the compositions of the invention enable fewer applicationsof the dosage form to the eye, which is generally preferred by patientpopulations. Moreover, the dosage applied is more effective, as thecationic property of the dosage form results in the drug “adhering” tothe eye, rather than having much of the dosage form run out of the eyesfollowing administration.

It is believed that the beneficial aspects of the novel opthalmiccyclosporine compositions of the invention result from a synergisticcombination of: (1) particle size of cyclosporine; (2) potentialpresence of cyclosporine in both a solubilized and particulate form inthe dosage; (3) the cationic property of the dosage form, and (4) thestable, non-irritating final product suitable for multi-dose packaging.

In general, tissues in the body are considered to be negatively charged.As a result, a positively-charged (cationic) product is considered tohave better chance of improved interaction of the product with thetissue. This improved interaction between the cationic product and bodytissues is not always observed, however.

Prior art describes that for a biphasic system, oil-soluble cationiclipids, e.g., stearylamine, has been used to impart a net positivecharge onto oil droplet, whereby the droplet being electrostaticallyattracted to the anionic surface of the eye. See, for example, U.S. Pat.No. 6,656,460.

When water-soluble, quaternary ammonium compounds are used, they willnot impart positive charge on the emulsion. Instead, they are likely tobe adsorbed or loosely bound onto the surface and may result in acharge. Typically, when quaternary ammonium compounds are used, theacidic pH needs to be maintained for protonation of the groups to impartpositive charge. In the present invention, it is unexpectedly found thatBKC induces positive charge, under about neutral pH, in a multi-phasiccomposition having a solid particulate phase and an oil phase dispersedin aqueous milieu. Surprisingly, the cationic emulsion prepared usingBKC shows significantly prolonged residence time in the eye using humancornea mounted on a Franz cell.

Due to the presence of the preservative, the formulations of the presentinvention can be packaged into multi-dose containers. Moreover, asdemonstrated in the following working examples, the presence ofcyclosporine was only detected locally and administration of theformulations of the invention does not cause any irritation to the eye.Hence, the formulations of the invention are suitable for dailyapplication.

7. Viscosity Modifier

The ophthalmic formulation may further comprise a viscosity modifier,such as a cellulose derivative, a polysaccharide or a synthetic polymer.The viscosity of the formulations of the present invention can beincreased without compromising other properties.

The following examples are given to illustrate the present invention. Itshould be understood, however, that the invention is not to be limitedto the specific conditions or details described in these examples.Throughout the specification, any and all references to a publiclyavailable document, including U.S. patents, are specificallyincorporated by reference.

EXAMPLE 1

The purpose of this example was to prepare formulations according to theinvention comprising cyclosporine and a cationic preservative,benzalkonium chloride.

The commercial Restasis® standard, which contains cyclosporine A (0.05%w/w) and inactive ingredients like glycerin, castor oil, polysorbate 80,carbomer 1342, purified water and sodium hydroxide, was used as acontrol for the purpose of comparing the properties of the formulation.

Cyclosporine is commercially available under the trade names SANDIMMUNE®and NEORAL®. It is a cyclic polypeptide immunosuppressant agentconsisting of 11 amino acids. It is produced as a metabolite by thefungus species Beauveria nlyea. Chemically, cyclosporine is designatedas[R-[R*,R*-(E)]]-cyclic(L-alanyl-D-alanyl-N-methyl-L-leucyl-N-methyl-L-leucyl-N-methyl-L-valyl-3-hydroxy-N,4-dimethyl-L-2-amino-6-octenoyl-L-α-amino-butyryl-N-methylglycyl-N-methyl-L-leucyl-L-valyl-N-methyl-L-leucyl).The chemical structure of cyclosporine (also known as cyclosporin A) is:

Cyclosporine was dissolved in ethanol at room temperature. Polysorbate80 and crodamol (Table 1) were then added to the cyclosporine solutionand mixed well with a paddle stirrer. Then benzalkonium chloridesolution and water were added and mixing was continued for about 5minutes. The coarse emulsion was then fed into a high pressurehomogenizer (APV Invensys, model APV-1000) and homogenized at 10,000 psifor three passes. The resultant 50× concentrated composition, describedbelow in Table 1, comprised cyclosporine dissolved in the solventethanol and nanoparticulate cyclosporine particles associated with thesurface stabilizer polysorbate 80 present in the water portion of theemulsion. The concentrated emulsion was collected and diluted withphosphate buffered saline (PBS), pH 7.2, at the ratio of 1 part ofconcentrated emulsion with 49 parts of PBS to obtain the final product,cationic micellar nanoparticle formulation (cMNP) of cyclosporine. ThecMNP and Restasis® have similar appearance as milky white emulsion. Theviscosity of the formulation of the invention can be increased withoutcompromising other properties.

The resultant particle size and zeta potential of cMNP of cyclosporinewere measured and compared with those of the commercial Restasis®standard, as shown in FIGS. 1A and 1B, as well as in Table 2.

TABLE 1 % w/w in 50X % w/w in 1X final Ingredient cMNP cMNP productCyclosporine 2.5 0.05 Ethanol 5.0 0.1 Polysorbate 80 5.0 0.1 Mediumchain 45.0 0.9 triglycerides (Crodamol GTCC) Benzalkonium chloride 1.250.025 Water 41.25 98.825

TABLE 2 Properties Restasis ® cMNP pH 6.5-8.0 7.23 Osmolality 230-320mOsm/Kg 308 mOsm/Kg Mean particle size 113 nm 167 nm Viscosity — 0.89mPa · s Mean zeta potential −35.0 mV +51.3 mV

EXAMPLE 2

The purpose of this example was to prepare formulations comprisingcyclosporine and a permeation enhancer, vitamin E TPGS. The formulationsof this example are used as a comparison to the formulations of theinvention prepared according to Example 1.

Cyclosporine and Restasis® standard are the same as those in Example 1.Vitamin E TPGS (d-alpha-tocopheryl polyethylene glycol-1000 succinate,obtained from Eastman Chemical Company) is a water-soluble form ofnatural-source vitamin E.

Cyclosporine was dissolved in ethanol at room temperature. Polysorbate80 and crodamol (Table 3) were then added to the cyclosporine solutionand mixed well with a paddle stirrer. Then vitamin E TPGS solution andwater were added and mixing was continued for about 5 minutes. Thecoarse emulsion was then fed into a high pressure homogenizer (APVInvensys, model APV-1000) and homogenized at 10,000 psi for threepasses. The resultant 50× concentrated composition, described below inTable 3, comprised cyclosporine dissolved in the solvent ethanol andnanoparticulate cyclosporine particles associated with the surfacestabilizer polysorbate 80 present in the water portion of the emulsion.The concentrated emulsion was collected and diluted with phosphatebuffered saline (PBS), pH 7.2, at the ratio of 1 part of concentratedemulsion with 49 parts of PBS to obtain the final product, neutralmicellar nanoparticle formulation (nMNP) of cyclosporine. The nMNP andRestasis® have similar appearance as milky while emulsion. The viscosityof the formulation of the invention can be increased withoutcompromising other properties.

The resultant particle size and zeta potential of nMNP of cyclosporinewere measured and compared with those of the commercial Restasis®standard, as shown in FIGS. 1A and 1C, as well as in Table 4.

TABLE 3 % w/w in 1X % w/w in 50X final nMNP Ingredient nMNP productCyclosporine 2.5 0.05 Ethanol 5.0 0.1 Polysorbate 80 5.0 0.1 Mediumchain 45.0 0.9 triglycerides (Crodamol GTCC) Vitamin E TPGS 1.25 0.025Water 41.25 98.825

TABLE 4 Properties Restasis ® nMNP pH 6.5-8.0 5.24 Osmolality 230-320mOsm/Kg 311 mOsm/Kg Mean particle size 113 nm 154 nm Viscosity — 0.87mPa · s Mean zeta potential −35.0 mV −4.15 mV

EXAMPLE 3

The purpose of this example was to test the formulations prepared inExample 1 and Example 2 for drug residence on cornea, for possibility ofonce-daily application, and for systemic absorption, using an in vitroFranz cell-human cornea assembly.

The protocol is as follows: isolated human cornea was obtained from aneye bank. The corneas were collected from donors and refrigerated in asuitable preservation medium. The preserved cornea was allowed to reachroom temperature for about 20 minutes, and then rinsed with PBS toremove the preservation medium. The corneas were mounted horizontallybetween the donor and receptor halves of the Franz diffusion cells. Thesurface area of the cornea exposed to the formulation in the donorchamber is 0.64 cm², and the receptor cell volume was 5.0 ml. Thereceptor compartment was filled with 0.01M PBS, pH 7.4, and ethanol at aratio of 9:1. A double water circulation jacket at 37° C. surrounds thereceptor cell in order to have the cornea temperature maintained atphysiologic level. The cMNP and nMNP formulations prepared according toExample 1 and Example 2, as well as the Restasis® standard, were appliedover the surface of the cornea gravimetrically using a syringe. Periodicsamples of 1.0 ml each were taken from the receptor cell to measure theamount of drug transporting across the cornea at time points of 0, 2, 4,8, and 24 hours, respectively. At each time point, the donor sample wasdiscarded and fresh donor sample was replenished. At the end of 24hours, the cornea were collected, washed and homogenized in PBS:ethanol(9:1) and assayed for drug residence.

No drug presence in the receptor compartment was detected at any timepoint. Hence, both formulations are suitable for once-daily applicationand the systemic availability of cyclosporine for both formulations isexpected to be at comparable level to that of Restasis®. Moreover, FIG.2 illustrates that significantly high level of cyclosporine was retainedin the cornea for the cMNP formulation prepared according to Example 1.Therefore, the cMNP formulation is expected to have a longer retentionwithin the cul-de-sac via electrostatic attraction with ocular tissue.

EXAMPLE 4

The purpose of this example was to test the formulations prepared inExample 1 and Example 2 for biocompatibility.

To determine the in vivo irritant and/or corrosive effects, the cMNP andnMNP formulations prepared according to Example 1 and Example 2 wereinstilled into the rabbit eye upon once-a-day application for 7consecutive days.

Six healthy New Zealand White rabbits were assigned to two groups ofthree animals per group. One group was dosed with the cMNP formulation,while the other was dosed with the nMNP formulation. All animals weredosed daily for seven consecutive days with 0.1 ml of the formulationinto the conjunctival sac of the left eye of each rabbit. The right eyeserved as the untreated control. The treated eyes were examined forirritation using the Draize technique, pretest, prior to each subsequentdose and at the time points of 24, 48 and 72 hours, respectively,following the final dose. Observations for mortality, toxicity andpharmacologic effects were made prior to each ocular observation period.Body weights were recorded pretest. The animals were humanely sacrificedusing CO₂, following the final observation.

The results show that there was no evidence of ocular irritation notedin any eye dosed with either the cMNP or the nMNP formulation and thatthere were no abnormal physical signs noted during the study. Hence,both the cMNP and the nMNP formulations are well-tolerated.

EXAMPLE 5

The purpose of this example was to test the formulations prepared inExample 1 and Example 2 for stability.

Both formulations were subjected to an in-house or informal non-ICHstability study. The storage temperatures and time points taken for thestability test are as follows:

1. 25° C.: 0, 1, 2, 4, 12, and 40 weeks;

2. 40° C.: 1, 2, 4 and 12 weeks;

3. 60° C.: 1 week

The stability data, in terms of the potency of cyclosporine and the meanparticle size, is depicted in FIG. 3 and FIG. 4, for the cMNPformulation and the nMNP formulation, respectively. For the cMNPformulation, the results show that there was no change in physicalappearance of the emulsion for any storage condition at any time pointtested. pH was stable at 7.3±0.3 across all storage conditions and timepointes tested. The cyclosporine content dropped by approximately 10%for 60° C. storage condition at 1-week time point. However, the 25° C.and 40° C. storage conditions did not cause any significant decrease inpotency during the test period. The mean particle size did not changeduring the test period for any storage condition tested. Hence, the cMNPformulation of cyclosporine will likely be stable for two years at roomtemperature. FIG. 4 shows that the nMNP formulation is stable for up to12 weeks at 25° C. or at 40° C.

EXAMPLE 6

The purpose of this example was to manufacture the cyclosporineformulation.

50× concentrated cyclosporine formulation containing 2.5% w/wcyclosporine is manufactured aseptically according to the description inExample 1 or Example 2. The particles of cyclosporine in theconcentrated product have a mean particle size of less than 200 nm.Subsequently, the concentrated composition is diluted with sterilePBS/saline to achieve 0.05% w/w cyclosporine in the final product, whichhas similar appearance to Restasis®. The final product is packaged andsealed in 0.4 ml per dose.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the methods and compositionsof the present invention without departing from the spirit or scope ofthe invention. Thus, it is intended that the present invention cover themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

What is claimed is:
 1. An ophthalmic nanoemulsion formulationcomprising: (a) a cyclosporine selected from the group consisting ofcyclosporines A, B, C, D and G, (b) ethanol, (c) at least one oil,wherein the oil comprises medium chain triglycerides, (d) at least onesurfactant, wherein the surfactant is a polysorbate, (e) at least onecationic preservative, and (f) water or phosphate buffered saline,wherein (i) the cyclosporine is in a solid particulate state and in asoluble state, (ii) the cyclosporine in the solid particulate state ispresent in the water or the phosphate buffered saline, (iii) theformulation is phospholipid-free, and (iv) the formulation comprisesglobules of oil comprising dissolved cyclosporine, wherein the globuleshave a mean diameter between 100 and 250 nm, wherein the at least onecationic preservative is selected from the group consisting ofcetyltrimethylammonium bromide, cetylpyridinium chloride, benzethoniumchloride, and benzalkonium chloride.
 2. The ophthalmic formulation ofclaim 1, wherein the cyclosporine is cyclosporine A.
 3. The ophthalmicformulation of claim 1, wherein the formulation is a mixture ofdissolved cyclosporine in the oil globules and the cyclosporine in thesolid particulate state is present in the water or the phosphatebuffered saline.
 4. The formulation of claim 1, wherein the at least onesurfactant is Polysorbate
 80. 5. The formulation of claim 1, furthercomprising a viscosity modifier.
 6. The formulation of claim 5, whereinthe viscosity modifier is selected from the group consisting of acellulose derivative, a polysaccharide and a synthetic polymer.
 7. Anophthalmic nanoemulsion formulation comprising: (a) a cyclosporineselected from the group consisting of cyclosporines A, B, C, D and G,(b) ethanol, (c) at least one oil, wherein the oil comprises mediumchain triglycerides, (d) at least one surfactant, wherein the surfactantis a polysorbate, (e) at least one cationic preservative, and (f) wateror phosphate buffered saline, wherein (i) the cyclosporine is in a solidparticulate state and in a soluble state, (ii) the cyclosporine in thesolid particulate state is present in the water or phosphate bufferedsaline, (iii) the formulation is phospholipid-free, and (iv) theformulation comprises globules of oil comprising dissolved cyclosporine,wherein the globules have a mean diameter between 100 and 250 nm,wherein the at least one cationic preservative is benzalkonium chloride.